1. An improved analytical expression for computing the leakage inductance of a circular bar in a semi-closed slot
- Author
-
Lorenzo Branz, Mauro Bortolozzi, Claudio Bruzzese, Alberto Tessarolo, IEEE, Bortolozzi, Mauro, Branz, Lorenzo, Tessarolo, Alberto, and Bruzzese, Claudio
- Subjects
semiclosed slot ,Engineering ,quirrel cage induction motors ,Saturation magnetization ,Poisson equation ,conductors (electric) ,finite element analysis ,induction motors ,magnetic leakage ,FEA ,approximated analytical formula ,circular bar leakage inductance computing ,electric machinery construction ,induction motor ,round conductive bar ,Geometry ,Inductance ,Induction motors ,Magnetic analysis ,Magnetic domains ,Analytical methods ,Poisson's equation ,rotor leakage inductance ,semi-closed slots ,squirrel cage induction motors ,Analytical method ,law.invention ,Magnetic analysi ,law ,Eddy current ,Electronic engineering ,Electrical conductor ,Leakage inductance ,business.industry ,Squirrel-cage rotor ,Mathematical analysis ,emi-closed slot ,finite element analysi ,Finite element method ,analytical methods ,emiclosed slot ,business ,Induction motor ,Magnetic domain - Abstract
Round conductive bars embedded in semi-closed slots are frequently used in the construction of electric machinery, for instance in the squirrel cage of induction motors. Frequently, such as in the study of induction motor steady-state performance at rated slip, it is useful to estimate the slot leakage inductance of these conductors under the hypothesis of no eddy currents and no magnetic saturation. This is usually done through simple approximated analytical formulas available in the literature. In this paper, an improved explicit ready-to-use leakage inductance expression for circular bars embedded in semi-closed slots is derived by solving Poisson's equation in the slot domain. The precision of the proposed formulation is assessed against Finite Element Analysis (FEA) for various slot geometries and is shown to always give very accurate results, with errors below 2%. Conversely, approximated simplified formulas available from the literature are demonstrated to possibly give large errors, which exceed 20% for some explored slot geometries.
- Published
- 2015